This is based on the rebelix part:
However, my frame's profile is different, so I fixed the problems in the scad which made the customization difficult. I've also removed the dependencies to other scads. (and replaced the czech comments with english)
The part includes a support for the plastic which goes to the slot, you might want this removed if your can manually place supports in your slicer.
The uploaded STL is set up for my profile (3030 with 6mm slot and M5 screws) It also includes the support set up for .2mm layer height.